Neurochemical characterization of pERK-expressing spinal neurons in histamine-induced itch.
Neurochemical characterization of pERK-expressing spinal neurons in histamine-induced itch.
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组胺引起的瘙痒中表达 pERK 的脊髓神经元的神经化学特征
DOI：
10.1038/srep12787
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发表时间：
2015-08-07
影响因子：
4.6
通讯作者：
Zhang L
中科院分区：
文献类型：
--
作者：
Jiang GY;Dai MH;Huang K;Chai GD;Chen JY;Chen L;Lang B;Wang QX;St Clair D;McCaig C;Ding YQ;Zhang L
急性瘙痒分为组胺依赖性和非组胺依赖性亚型，我们之前的研究表明，组胺引起的瘙痒感需要选择性激活脊髓背角（SDH）中的 ERK 信号传导。探索脊髓瘙痒感的机制需要表达 pERK 的神经元的形态特征。为了研究表达 pERK 的神经元是否是脊髓上投射神经元，我们将 Fluorogold (FG) 注射到腹基底丘脑复合体 (VB) 和臂旁区域，这是啮齿动物的两个主要脊柱上升部位。少数（1%）pERK 阳性神经元被 FG 标记，表明组胺诱导的 ERK 激活主要位于局部 SDH 神经元。然后，我们检查了 pERK 与兴奋性神经元表达的 Calbindin 和 Lmx1b 的共定位，发现超过一半 (58%) 的 pERK 阳性神经元表达 Lmx1b，但没有观察到与 Calbindin 的共表达。另一方面，大约 7% 的 pERK 阳性神经元表达 GAD67，其中 27% 含有 Pax2。这些结果支持这样的观点：表达 pERK 的神经元是处理脊髓瘙痒感的局部神经元回路的组成部分。
Acute itch is divided into histamine- and non-histamine-dependent subtypes and our previous study has shown that activation of ERK signaling in the spinal dorsal horn (SDH) is required selectively for histamine-induced itch sensation. Morphological characteristics of pERK-expressing neurons are required for exploring the mechanism underlying spinal itch sensation. To investigate whether pERK-expressing neurons are supraspinally-projecting neurons, we injected Fluorogold (FG) into the ventrobasal thalamic complex (VB) and parabrachial region, the two major spinal ascending sites in rodents. A small number (1%) of pERK-positive neurons were labeled by FG, suggesting that histamine-induced activation of ERK is primarily located in local SDH neurons. We then examined the co-localization of pERK with Calbindin and Lmx1b, which are expressed by excitatory neurons and found that more than half (58%) of pERK-positive neurons expressed Lmx1b, but no co-expression with Calbindin was observed. On the other hand, approximately 7% of pERK-positive neurons expressed GAD67 and 27% of them contained Pax2. These results support the idea that pERK-expressing neurons serve as a component of local neuronal circuits for processing itch sensation in the spinal cord.